Specs in oracle/truffleruby@09cac1a

It's actually more complex than that since Ruby 2.4.4: on require "foo/bar", the foo/bar.rb part is not canonicalized, but the entry in $LOAD_PATH with that file in it is canonicalized.

So this essentially needs a fix in Bundler (rubygems/bundler#6502) and/or RVM (to avoid symlinks in GEM_PATH.).

Note that this is also causing "issues" when exceptions are raised from symlink-pathed files, as seen in #5436. Unclear how critical that particular case is, though, since it was only found due to error path-inspecting specs in Pry.

Remaining failures as of today:

• Kernel#require_relative with a relative path ($LOADED_FEATURES) with symlinks does not canonicalize the path and stores a path with symlinks
• Kernel#require ($LOADED_FEATURES) with symlinks does not canonicalize the path and stores a path with symlinks
• Kernel#require ($LOADED_FEATURES) with symlinks in the required feature and $LOAD_PATH canonicalizes the entry in $LOAD_PATH but not the filename passed to #require
• Kernel.require ($LOADED_FEATURES) with symlinks does not canonicalize the path and stores a path with symlinks
• Kernel.require ($LOADED_FEATURES) with symlinks in the required feature and $LOAD_PATH canonicalizes the entry in $LOAD_PATH but not the filename passed to #require
• Thread::Backtrace::Location#absolute_path canonicalization returns a canonical path without symlinks, even when __FILE__ does not
• Thread::Backtrace::Location#absolute_path canonicalization returns a canonical path without symlinks, even when __FILE__ is removed
• Thread::Backtrace::Location#path canonicalization returns a non-canonical path with symlinks, the same as __FILE__

Some or all of this could be fixed for 9.3 with final audits and fixes for load/require so I will leave this targeted for now.